Photo eyepiece for endoscopes
AssigneeOlympus Optical Co., Ltd.
InventorsNobuo Yamashita, Miwako Maeda
Life of this patent
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Abstract
A photo eyepiece for endoscopes comprising at least two cemented lens components, i.e., a first cemented lens component and a second cemented lens component, having a large numerical aperture and, in spite of this merit, corrected very favorably in characteristics of spherical aberration, lateral chromatic aberration and curvature of field.
Claims4
A photo eyepiece for endoscopes comprising a positive cemented meniscus lens component having a concave surface on the object side, a positive lens component, a positive meniscus lens component having a convex surface on the object side and a negative cemented meniscus lens component having a convex surface on the object side, and said photo eyepiece system satisfying the following conditions:
- (1) .nu..sub.1p -.nu..sub.1n >.nu..sub.2p -.nu..sub.2n
- (2) 0.43f<R<0.47f wherein the reference symbols .nu..sub.1p and .nu..sub.1n represent Abbe's numbers of the positive and negative elements respectively of said positive cemented meniscus lens component, the reference symbols .nu..sub.2p and .nu..sub.2n designate Abbe's numbers of the positive and negative elements respectively of said negative cemented meniscus lens component, the reference symbol R denotes radius of curvature on the surface located on the extreme image side and the reference symbol f represents focal length of the photo eyepiece system as a whole.
Dependencies are inferred from the claim text.